speaker wire polarity - AVS Forum
Speakers > speaker wire polarity
jbhxray's Avatar jbhxray 07:26 PM 02-21-2008
I bought 14 gague generic speaker cable from Lowe's. I am in the process of wiring my speakers and I find I can't tell + from - polarity on the wires. I do not see any indication marked and both wires are copper. Is there a simple way to make sure I am correctly wiring + and - ? Any help appreciated.

Beta_max's Avatar Beta_max 08:06 PM 02-21-2008
You mean the cable is the same color?
oztech's Avatar oztech 08:28 PM 02-21-2008
One side will usually have ribs or a stripe if no markings at all you will have to use
a toner to make sure ,lowe's has them.
Patdeisa's Avatar Patdeisa 08:54 PM 02-21-2008
I have two speaker wires that have the same problem. One has printing on it, which makes it able to identify the same strand, so I just use that as negative (it doesn't matter, as long as you're consistant). The other has a green thread mixed in with the copper on one side- very hard to see, but can be used to identify it.

If nothing else, use a black marker and follow the wire yourself and label the ends.
jbhxray's Avatar jbhxray 06:44 AM 02-22-2008
Thanks for replys. What is this toner you speak of? I do not see any markings on the wire and some of it is already in the walls.
Thanks
Noubourne's Avatar Noubourne 07:13 AM 02-22-2008
A toner is a two-piece device; a transmitter and a receiver.

You connect the transmitter to one of the wires, and then use the receiver to check the other end of the wires. When you connect the receiver to the same wire that the transmitter is on, you will hear the signal (usually a steady tone or beeping) coming from the transmitter. This helps you to know which wire you have on both sides, even if you've already installed them in some walls.

It was one of my best tools when I was a cable installer - especially considering the price of my other meters.
jbhxray's Avatar jbhxray 07:34 AM 02-22-2008
Thanks for the info. Where is the best place to get this and what is price estimate?
ajstan99's Avatar ajstan99 07:58 AM 02-22-2008
I haven't tried it, but this looks to be an inexpensive way to determine polarity:
http://www.sweetwater.com/expert-cen.../d--04/20/2007

"Disconnect the speaker wire from your amp, then connect the cable to a 9-volt battery. The battery's DC voltage will cause the woofers to move forward if the polarity is correct (that is, positive to positive). If the woofer moves backward, your polarity is reversed. If that's the case, simply reverse the connection on your amp."

Then, put on some color-coded banana plugs so you won't have to test the wire again.
sivadselim's Avatar sivadselim 01:39 PM 02-22-2008
Quote:
Originally Posted by jbhxray View Post

Thanks for the info. Where is the best place to get this and what is price estimate?

All you need is something that will measure continuity. There are some relatively inexpensive devices made for doing this. There are some simple continuity testers in which will illuminate an LED indicator light when a circuit is completed. Check your local hardware store, mega home imnprovement store, or Radio Shack. A voltmeter, ohmeter, or multimeter will work, too; also available form the same places.

But there should be SOMETHING that distinguishes one strand from another. Lettering? A "rib". Something. If not, I would not use it. It's just going to be a pain in the ass.
WAR_GA's Avatar WAR_GA 03:15 PM 07-13-2008
Blame it on the wife . . . I too bought the same wire at Lowes. At the store I told her I could not see a difference in the two sides of the wire. She looked at the picture on the spool and said, one side should be black and the other side copper after you cut them.

After stripping the wire and seeing that both sides looked the same, I searched the forum for this issue. The response I was using was as a fix was - mark one side and run down the length of the wire and mark the other end.

As I was stripping, complaining, and marking the wire and my wife was hooking up our new Axiom Epic 80 system, she commented "did you know one edge of the cable is flat and the other edge is round?" There's the answer to determining polarity on Lowe's speaker wire. I hate that she is both more mechanical and smarter than me on issues such as this!
sivadselim's Avatar sivadselim 04:06 PM 07-13-2008
Quote:
Originally Posted by WAR_GA View Post

I hate that she is both more mechanical and smarter than me on issues such as this!

They ARE useful for some things.
pmf's Avatar pmf 06:14 PM 07-13-2008
Are you sure your wife wasn't alluding to the fact that the outside edges of a double stranded wire being round and the inside edges (where the 2 strands came fused together till you pull them apart) being more square (flat), or the other way around?

The way I check continuity is to use a speaker (old car speaker should work fine) & connect it's terminals to the + & - or a AA battery to make clicking noises. Get the speaker & the AA battery with one terminal already hooked up & use the open terimal(s) on the 2 ends of your cable in doubt to look for continuity.

PF
quadriverfalls's Avatar quadriverfalls 10:35 PM 07-13-2008
Quote:
Originally Posted by jbhxray View Post

I do not see any markings on the wire and some of it is already in the walls.
Thanks

Sounds like you used generic speaker wire which is NOT rated CL-2 or CL-3 for in wall use. If you should happen to have a fire, and it is discovered that you used improper wiring inside your walls (whether that caused the fire or not is irrelevent), your insurance company can deny your claim and cancel you without cause.

You should ALWAYS use jacketed CL-2 or CL-3 rated speaker wire when running it inside a wall or ceiling cavity.
Easyaspie's Avatar Easyaspie 09:13 AM 07-14-2008
Quote:
Originally Posted by quadriverfalls View Post

Sounds like you used generic speaker wire which is NOT rated CL-2 or CL-3 for in wall use. If you should happen to have a fire, and it is discovered that you used improper wiring inside your walls (whether that caused the fire or not is irrelevent), your insurance company can deny your claim and cancel you without cause.

You should ALWAYS use jacketed CL-2 or CL-3 rated speaker wire when running it inside a wall or ceiling cavity.

Excellent point.
sivadselim's Avatar sivadselim 09:28 AM 07-14-2008
Quote:
Originally Posted by quadriverfalls View Post

Sounds like you used generic speaker wire which is NOT rated CL-2 or CL-3 for in wall use. If you should happen to have a fire, and it is discovered that you used improper wiring inside your walls (whether that caused the fire or not is irrelevent), your insurance company can deny your claim and cancel you without cause.

You should ALWAYS use jacketed CL-2 or CL-3 rated speaker wire when running it inside a wall or ceiling cavity.

Unrelated but still relevant. And it may be too late.

Add to this the fact that if there IS a fire and you survive the flames, toxic fumes from the burning of the non-CL2/3 wire may kill you.
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